Design Observer links to a piece from architect Michael McDonough on the top ten things they didn't teach him in design school. Though pitched to professional designers, McDonough also offers sound advice on problem demolition. Yes, the two are related.
Of his top ten, "if everything is equally important than nothing is very important," "Don't over-think a problem" and "start with what you know; then remove the unknowns" stood out to me.
The first two bear on the idea of decision-making (as in, "make one!") because making decisions and not revisiting them is a highly underrated method of work. I struggle with second guessing myself.
The third point is important because hidden in every problem is the single issue on which the problem turns. Removing what's unecessary is an exercise in addition by subtraction. As a method of problem solving, abstraction is what is, essentially.